How To Confirm Paternity Of A Child?

i have an embarrassing moment that happen to me some yrs ago ok i had sex with a guy and the condom got stuck in me i didn't notice to later that night it was full of semen however i ended up having a baby nine months from then i missed my period the month after this occurrence then it returned for one month then never to return in between this all i had intercourse with someone else unprotected so my question is can i have possibly gotten pregnant by the condom being stuck in me cuz right now im seeking paternity for the child or is it a waste of time